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AST_ISA$<$CLASS$>$ - Test membership of a class by an Object

Description:
This is a family of functions which test whether an Object is a member of the class called $<$CLASS$>$, or of any class derived from it.
Invocation:
RESULT = AST_ISA$<$CLASS$>$( THIS, STATUS )
Arguments:
THIS = INTEGER (Given)
Pointer to the Object.
STATUS = INTEGER (Given and Returned)
The global status.
Class Applicability:
Object
These functions apply to all Objects.
Returned Value:
AST_ISA$<$CLASS$>$ = LOGICAL
.TRUE. if the Object belongs to the class called $<$CLASS$>$ (or to a class derived from it), otherwise .FALSE..
Examples:
MEMBER = AST_ISAFRAME( OBJ, STATUS );

Tests whether Object OBJ is a member of the Frame class, or of any class derived from a Frame.
Notes:
  • Every AST class provides a function (AST_ISA$<$CLASS$>$) of this form, where $<$CLASS$>$ should be replaced by the class name.

  • This function attempts to execute even if STATUS is set to an error value on entry, although no further error report will be made if it subsequently fails under these circumstances.

  • A value of .FALSE. will be returned if this function should fail for any reason. In particular, it will fail if the pointer supplied does not identify an Object of any sort.


next up previous 264
Next: AST_KEYMAP - Create a KeyMap
Up: AST Routine Descriptions
Previous: AST_INVERT - Invert a Mapping

AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 210
R.F. Warren-Smith & D.S. Berry
24th May 2011
E-mail:ussc@star.rl.ac.uk

Copyright (C) 2009 Science \& Technology Facilities Council